[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: CNN on Lungs and Feathers (LONG)



At 09:33 AM 12/26/97 +0200, Bryan R. Stahl wrote:
>Thought this may be of interest to the list:
>
>Lung Fossils Suggest Dinos Breathed in Cold Blood
>
>
>Science
>25-DEC-97
>By Ann Gibbons

None of this is really very new.  It is just a rehash of Ruben et alii's
paper from a month or two ago.

And Ruben is almost certainly wrong.  There is solid evidence for pneumatic
cavities in cervical and anterior dorsal vertebrae in all known theropods
(except perhaps the herrerasaurids and _Eoraptor_ - I do not remember for
certain).  This means that the cervical air-sac already existed *long*
before _Sinosauropteryx_ evolved.   And pneumatic spaces in the posterior
dorsal, pelvis, and hind-limbs is known from some non-avian coelurosaurs.
This means that the *abdominal* air-sac existed by then.

Note, also, that the fact that the cervical air-sac seems to have preceded
the abdominal one eliminates Ruben's objection to air-sacs co-existing with
a diaphragm.  (Though, of course, the abdominal air-sac could have existed
prior to invading the posterior bones).

--------------
May the peace of God be with you.         sarima@ix.netcom.com
                                          sfriesen@netlock.com